Connection to MSSQLServer 2008R2 works fine in Unity Editor, but when it deployed into android device, the connection cannot be open. What should I do?

I am so happy when trying connecting to sql is success in unity3D editor. But not when it deployed to device.

I have copied System.Configuration.dll, System.Data.dll, System.Data.Linq.dll, System.EnterpriseServices.dll to Assets folder.

Here is my code:

using UnityEngine; using System.Collections; using System.Data; using System.Data.SqlClient;

public class FS_SQLConnect : MonoBehaviour {

 public UILabel label;
 public string ServerName;
 public string DatabaseName;
 public string UserID;
 public string Password;
 
 public UILabel status;
 
 
 private static IDbConnection dbConnection;
 
 public bool openSqlConnection() {

//check 1

         string connectionString = 
          "Server="+ ServerName +";" +
          "Database="+ DatabaseName + ";" +
          "User ID="+ UserID +";" +
          "Password=" + Password";
         

//check 2

     dbConnection = (IDbConnection)new SqlConnection(connectionString);

//check 3

     dbConnection.Open();
         

//check 4

     Debug.Log("Connected to database.");

         return true;
     }
     catch(SqlException ex)
     {
         label.text = ex.ToString();
         return false;
     }
     catch(UnityException ex)
     {
         label.text = ex.ToString();
         return false;
     }
     return false;
 }

When deployed to device, it always stop in dbConnection.Open(); //check 3

I have try:

• Connecting my PC and android device to same Wifi, and try to ping from device to PC(worked).

• Creating Hotspot from PC, then android device connected to it

• Enable TCP/IP Connection in SQL Server Network Configuration for MSSQLSERVER

When I give wrong PC IP Address, the device says an error that server could not be found When I give wrong password to connectionString, the device says failed to Login

But when I give correct IP, DatabaseName, UserID and password. There is 2 condition: When firewall is on, it says: System.Data.SqlClient.SqlException: Timeout expired.

When firewall is off: nothing happen, when I'm trying to change a label text in every "check" (comment on my code), it stop in check 3(means it failed when opening connection). and connectionState says it still closed :(

Sorry for long description. Please help me :(

Thank you :)